feat: add rust solution to lc problem: No.0239 (doocs#1156)

Author: xzhseh

solution/0200-0299/0239.Sliding Window Maximum/README.md

@@ -206,6 +206,42 @@ public:
 };
 ```
 
+### **Rust**
+
+```rust
+use std::collections::VecDeque;
+
+impl Solution {
+    #[allow(dead_code)]
+    pub fn max_sliding_window(nums: Vec<i32>, k: i32) -> Vec<i32> {
+        // The deque contains the index of `nums`
+        let mut q: VecDeque<usize> = VecDeque::new();
+        let mut ans_vec: Vec<i32> = Vec::new();
+
+        for i in 0..nums.len() {
+            // Check the first element of queue, if it's out of bound
+            if !q.is_empty() && (i as i32 - k + 1) > *q.front().unwrap() as i32 {
+                // Pop it out
+                q.pop_front();
+            }
+            // Pop back elements out until either the deque is empty
+            // Or the back element is greater than the current traversed element
+            while !q.is_empty() && nums[*q.back().unwrap()] <= nums[i] {
+                q.pop_back();
+            }
+            // Push the current index in queue
+            q.push_back(i);
+            // Check if the condition is satisfied
+            if i >= (k - 1) as usize {
+                ans_vec.push(nums[*q.front().unwrap()]);
+            }
+        }
+
+        ans_vec
+    }
+}
+```
+
 ### **Go**
 
 ```go

solution/0200-0299/0239.Sliding Window Maximum/README_EN.md

@@ -171,6 +171,42 @@ public:
 };
 ```
 
+### **Rust**
+
+```rust
+use std::collections::VecDeque;
+
+impl Solution {
+    #[allow(dead_code)]
+    pub fn max_sliding_window(nums: Vec<i32>, k: i32) -> Vec<i32> {
+        // The deque contains the index of `nums`
+        let mut q: VecDeque<usize> = VecDeque::new();
+        let mut ans_vec: Vec<i32> = Vec::new();
+
+        for i in 0..nums.len() {
+            // Check the first element of queue, if it's out of bound
+            if !q.is_empty() && (i as i32 - k + 1) > *q.front().unwrap() as i32 {
+                // Pop it out
+                q.pop_front();
+            }
+            // Pop back elements out until either the deque is empty
+            // Or the back element is greater than the current traversed element
+            while !q.is_empty() && nums[*q.back().unwrap()] <= nums[i] {
+                q.pop_back();
+            }
+            // Push the current index in queue
+            q.push_back(i);
+            // Check if the condition is satisfied
+            if i >= (k - 1) as usize {
+                ans_vec.push(nums[*q.front().unwrap()]);
+            }
+        }
+
+        ans_vec
+    }
+}
+```
+
 ### **Go**
 
 ```go

solution/0200-0299/0239.Sliding Window Maximum/Solution.rs

@@ -0,0 +1,31 @@
+use std::collections::VecDeque;
+
+impl Solution {
+    #[allow(dead_code)]
+    pub fn max_sliding_window(nums: Vec<i32>, k: i32) -> Vec<i32> {
+        // The deque contains the index of `nums`
+        let mut q: VecDeque<usize> = VecDeque::new();
+        let mut ans_vec: Vec<i32> = Vec::new();
+
+        for i in 0..nums.len() {
+            // Check the first element of queue, if it's out of bound
+            if !q.is_empty() && (i as i32 - k + 1) > *q.front().unwrap() as i32 {
+                // Pop it out
+                q.pop_front();
+            }
+            // Pop back elements out until either the deque is empty
+            // Or the back element is greater than the current traversed element
+            while !q.is_empty() && nums[*q.back().unwrap()] <= nums[i] {
+                q.pop_back();
+            }
+            // Push the current index in queue
+            q.push_back(i);
+            // Check if the condition is satisfied
+            if i >= (k - 1) as usize {
+                ans_vec.push(nums[*q.front().unwrap()]);
+            }
+        }
+
+        ans_vec
+    }
+}